For some time, as set forth in Patent Document 1 (Japanese Published Unexamined Patent Application 2013-44178), flush toilets have been known wherein in a wash-down type of flush toilet wherein a gravity feed storage tank is disposed as a water supply apparatus at the rear top portion of a flush toilet, the inside perimeter surface of the rim portion is formed to rise in an essentially plumb direction, and flush water is spouted from a rim spout port formed in the front region, to perform a flush as it circulates over the interior of the bowl portion.